With the rapid development of technology, some wearable accessories, such as prayer beads, have been electronicized to become wearable electronic devices having functions such as automatic counting, time displaying and wireless communicating. Generally, a string of prayer beads includes a string and multiple beads strung on the string, and the string of the prayer beads is usually annular. The electronic components are disposed in a primary bead to enable the connection and interaction of the electronic components. Due to the desire for compactness of electronic devices in recent years, the size of the wearable electronic device has been reduced to satisfy this desire for a compact size.